Bug#991468: Can't add GtkHeaderBar to "Client side window decoration" area

[Osamu Aoki]

Package: glade
Version: 3.38.2-2
Severity: normal

I know Debian can't do feature improvement.  So this is more-or-less a
public service memo for `<placeholder/>`  to Glade users until future
Glade fix this sloppy and not so well documented Glade behavior.

When things are too complicated to handle for Glade (such as relatively
new feature supports), Glade sometimes give up creating the proper XML
content for us and we need to use text editor to fix the sloppy XML to
create the usable XML.

One noticeable case is "Client side window decoration" area and another
is the area created by "GtkPopoverMenu".  If you try to add some graphic
widget to the intended area using Glade GUI operation, Glade gives you
"... need placeholder to add children" as a part of error message and
refuse to do expected.  Yes, this is sad.

Please look at upstream issue page I updated with my workaround:
  https://gitlab.gnome.org/GNOME/glade/-/issues/499

I think the manual workaround I proposed there is non-trivial.

Once you see the inside of the XML file with the text editor and compare
this with recently published modern UI XML files out there, you
understand `<placeholder/>` needs to be replaced with the manually
crafted proper XML content.

I hope this helps people to work around this sloppy Glade generated XML
file issue.  (At least, it took me a while to find my solution.)

HTH.

-- System Information:
Debian Release: 11.0
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 5.10.0-8-amd64 (SMP w/12 CPU threads)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages glade depends on:
ii  libc6                2.31-12
ii  libcairo2            1.16.0-5
ii  libgdk-pixbuf-2.0-0  2.42.2+dfsg-1
ii  libgladeui-2-13      3.38.2-2
ii  libglib2.0-0         2.66.8-1
ii  libgtk-3-0           3.24.24-4
ii  libpango-1.0-0       1.46.2-3
ii  libxml2              2.9.10+dfsg-6.7

Versions of packages glade recommends:
ii  devhelp       3.38.1-1
ii  libgtk-3-dev  3.24.24-4

glade suggests no packages.

-- no debconf information